Bilateral maxillary sinus mucosal thickening indicates the presence of inflammation, such as chronic sinusitis, maxillary sinus cysts and so on. It is recommended that the patient consult a doctor in time, according to the doctor’s instructions for drug treatment, if necessary, surgical treatment. 1. Chronic sinusitis: usually due to acute sinusitis, odontogenic infection, trauma and foreign body, as well as nasal polyps, turbinate hypertrophy and other obstructive causes in the nasal cavity, usually there will be nasal congestion, pus flow, olfactory dysfunction, headache and other manifestations. If left untreated, it can cause intraorbital infection or intracranial infection, with symptoms such as periorbital swelling, displacement of the eyeball and paralysis of the eye muscles. 2. Maxillary sinus cyst: it is usually caused by infection, inflammation, tumor, trauma, allergy, rhinitis and other stimulation of sinus mucosa or mucosal gland blockage. Early cysts are small, there is no obvious clinical symptoms. When the cyst increases in size and even fills the whole nasal cavity, nasal congestion, runny nose, swollen cheeks, headache, diplopia and other manifestations will occur. Bilateral maxillary sinus mucosal thickening is the imaging description of nasal CT, and it is recommended that the patient seek professional consultation in time, and symptomatic treatment according to the cause of the disease.